More

EF-4 Tornadoes Are Rare For North Texas

GRANBURY (CBSDFW.COM) – It was the deadliest tornado outbreak in North Texas in over 30 years, and Granbury was the hardest-hit area in all of DFW. The National Weather Service estimated that 16 twisters landed across North Texas, and some of them were EF-4 tornadoes.

What does that mean?

Storms of that strength are extremely rare. In the last 50 years, North Texas has only seen six EF-4 tornadoes, about one each decade. And even the total number of twisters was rare. In the last 50 years, there have only been seven days with 10 or more tornadoes.

The six fatalities on Wednesday made it the deadliest North Texas tornado day since April 1982, when a storm ripped through Paris.

A survey team from the National Weather Service walked through the damage on Thursday to determine the classification information. They look at several factors when trying to determine the strength of any particular storm. An EF-4 tornado has winds over 200 mph, and there can be signs that such a strong storm has passed through a neighborhood.

The survey team looked for the total loss of well-built homes and business structures, and large trucks that were either flipped repeatedly or moved short distances. They also looked for trees that were debarked and snapped close to the ground, or uprooted altogether.

An EF-4 tornado levels homes and practically requires a storm shelter in order to survive. And when you look at some of the damage done by these powerful twisters on Wednesday, it is almost unbelievable that there were not more deaths.

Jeff joined CBS 11 and TXA 21 in December 2010. He came to North Texas from Nashville, where he spent the past 11 years, most recently as the morning meteorologist at WKRN-TV. His career has also taken him to Kansas City, Mo., where he was the seni...